#!/usr/bin/env python3

import logging
import os
import pathlib
import subprocess
import tempfile
from typing import Optional

import requests
from praw.models import Submission

from bulkredditdownloader.authenticator import Authenticator
from bulkredditdownloader.resource import Resource
from bulkredditdownloader.site_downloaders.base_downloader import BaseDownloader

logger = logging.getLogger(__name__)


class VReddit(BaseDownloader):
    def __init__(self, post: Submission):
        super().__init__(post)

    def find_resources(self, authenticator: Optional[Authenticator] = None) -> list[Resource]:
        try:
            fnull = open(os.devnull, 'w')
            subprocess.call("ffmpeg", stdout=fnull, stderr=subprocess.STDOUT)
        except subprocess.SubprocessError:
            return [Resource(self.post, self.post.url)]
        else:
            video_url = self.post.url
            audio_url = video_url[:video_url.rfind('/')] + '/DASH_audio.mp4'

            with tempfile.TemporaryDirectory() as temp_dir:
                video = requests.get(video_url).content
                audio = requests.get(audio_url).content
                with open(temp_dir / 'video', 'wb')as file:
                    file.write(video)
                with open(temp_dir / 'audio', 'wb') as file:
                    file.write(audio)
                self._merge_audio(temp_dir)
                with open(temp_dir / 'output.mp4', 'rb') as file:
                    content = file.read()
            out = Resource(self.post, self.post.url)
            out.content = content
            return out

    @staticmethod
    def _merge_audio(working_directory: pathlib.Path):
        input_video = working_directory / 'video'
        input_audio = working_directory / 'audio'

        fnull = open(os.devnull, 'w')
        cmd = "ffmpeg -i {} -i {} -c:v copy -c:a aac -strict experimental {}".format(
            input_audio, input_video, str(working_directory / 'output.mp4'))
        subprocess.call(cmd.split(), stdout=fnull, stderr=subprocess.STDOUT)